Madison Area Lyme Support Group

A dog can be man’s best friend, particularly when it comes to helping identify the risk of tick-borne diseases for humans. The true spread of Babesia may currently be underestimated, under-reported, and untreated, writes Mahachi and colleagues in the journal Parasites Vectors.¹ But new research indicates that hunting dogs can offer insight into the distribution of Babesia in the Southern and Western USA.

Investigators looked at several tick-transmitted diseases including Babesia, in dogs, to help determine potential risks to humans. Hunting dogs, specifically, were tracked as they are exposed to ticks more often than pet dogs. And they are more likely to be outdoors for long periods in tick habitats and less likely to be groomed for ticks by their owner.

Furthermore,

“A recent occupational study found that those who work with hunting dogs compared to those who work in high-risk tick environments, were 5.83 times more likely to report having found embedded ticks on their bodies,” writes Mahachi. 

The authors examined the incidence of Lyme disease, ehrlichiosis, anaplasmosis, and Babesia in hunting dogs. But they excluded dogs that were symptomatic with Lyme disease, ehrlichiosis, and anaplasmosis.

Study findings

They found,

“Unlike B. burgdorferi and Anaplasma spp., the highest number of seroprevalent dogs with Babesia spp. was in the Midwest (52.5%) and South (50%) and the lowest numbers in the West (32.6%), with high levels across all regions.”

The hunting dogs also had a high rate of co-infection with Borrelia burgdorferi and Anaplasma spp. The presence of co-infections, however, was not a surprise to investigators, given that past studies have found

“up to 40% of patients with Lyme disease experienced concurrent babesiosis infections and 13% experienced concurrent Anaplasma infections.”

The authors also examined seropositivity results over three time periods, January – February, August and November.

“Our results show that Babesia spp., Ba. gibsoni, and B. burgdorferi seropositivity remained elevated across all three time points.”

“It is important for healthcare workers to take note of current region and regions veterinary patients and their owners may have visited when considering tick-borne disease diagnoses,” writes Mahachi.

Unfortunately, the surveillance of tick-borne diseases, such as Babesia, in dogs has been limited due to a lack of centralized federal surveillance or mandate.

But, the authors write,

“given the close interaction between dogs and people, dogs can serve as an important sentinel species to help track vector-borne disease risks by monitoring trends of infection from tick-borne pathogens in dogs.”

Over the past two decades, there have been reports of the tick-borne infection Babesia microti being imported into foreign countries from the United States. International travelers are unknowingly carrying the disease into countries, which may be unfamiliar with diagnosing tick-borne illnesses.

“Recently, sporadic cases of human babesiosis caused by several species of Babesia have been reported in other countries,” write the authors of “Imported Human Babesiosis, Singapore, 2018.” [1] These cases include:

• Babesia microti (Germany, Australia, South Korea)
• Babesia microti-like (Japan, Taiwan, China)
• Babesia duncani (United States, Canada)
• Babesia divergens (Europe)
• Babesia venatorum (Europe, China)
• Babesia crassa-like (China)
• Babesia motasi-like (South Korea)

Additionally, in 2003, Nohýnková and colleagues reported what was believed to be the first case of symptomatic Babesia microti infection imported into the Czech Republic from the United States. [2] Meanwhile in 2013, investigators described the “first human case of Babesia microti infection imported to Denmark from the United States by a 64-year-old female traveler with fever of unknown origin.” [3]

READ MORE: Tourists visiting the United States contract Babesia, leaving one dead

According to the authors, “The case raises the possibility that Babesia infections may be under-diagnosed, [and] illustrates the importance of a thorough travel history…” [3]

The number of international travelers carrying tick-borne diseases into foreign countries is rising, making it increasingly important for clinicians to gather a thorough travel history on patients. CLICK TO TWEET 

Two recent case reports demonstrate the rise of tick-borne diseases being imported into other countries and highlights the challenges clinicians face in distinguishing these illnesses, specifically Babesia microti, from malaria.

Case 1: Singapore

A 37-year-old man traveled to multiple places in the year before his illness. His travel history included Vietnam, Thailand, Indonesia, Cambodia, Indonesia, and the United States.

On June 17, 2018, after visiting the Northeastern USA, he noted a right ankle papule that lasted 3 weeks. “He sought consultation at a travel clinic [in Singapore] because of high fever (104°F), rigors, and headaches, which had persisted and worsened over 18 days,” writes Lim and colleagues. [1]

Doctors had prescribed amoxicillin, but the symptoms persisted.

LISTEN TO PODCAST: Babesia treatment of two travelers

“Laboratory test results revealed moderate thrombocytopenia and anemia, and malaria blood films revealed trophozoites forming in erythrocytes, suggestive of Babesia,” writes Lin.

The doctors confirmed the diagnosis of Babesia microti with additional testing. He was treated successfully with quinine and clindamycin.

Case 2: Spain

“A 72-year-old man with a 15-day history of fever, generalized arthralgia, asthenia, and decreased appetite was admitted to Hospital Universitario San Cecilio, Granada, Spain,” writes Guirao-Arrabal and colleagues in “Imported babesiosis caused by Babesia microti − A case report.” [4]

The man had a history of sweating and his inflammatory markers were elevated. He also had a history of type 2 diabetes.

He reportedly traveled to a park in Westchester County, NY, an area that is considered endemic for babesiosis.

Malaria was considered based on intraerythrocytic forms in the red cells. The malaria antigen and PCR tests for malaria were negative.

Babesia microti was presumed with a low level of parasitemia (0.5 %). There was no evidence of another tick-borne illness. After treatment with atovaquone and azithromycin, his parasitemia resolved.

Editor’s note: It is encouraging to see that Babesia is now being considered by clinicians and treated appropriately.

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For more:  https://madisonarealymesupportgroup.com/category/babesia-treatment/